Surgical protocol for fixation of bone using inflatable device

ABSTRACT

A method and apparatus for the fixation of osteoporotic and non-osteoporotic bones and especially vertebral body compression fractures, Colles&#39; fractures and fractures of the proximal humerus. The method of the present invention includes a series of steps including penetrating the bone having the fracture with a guide pin, drilling the bone marrow of the bone to enlarge the cavity to be treated, following which a bone specific inflatable device is inserted in the cavity and inflated. The expansion of the device causes a compacting of the bone marrow against the inner surface of the outer wall of the bone to be treated to further enlarge the cavity. When this occurs, a flowable synthetic bone material or methyl methacrylate cement is directed into the cavity and allowed to set to a hardened condition. Following this, the instruments are removed. In the fixation of vertebral body fractures, an elliptical inflatable device is first used to initiate the compacting of the bone marrow, following which a substantially cylindrical inflatable device is inserted into the cavity to further compact the bone marrow in all directions. In the fixation of Colles&#39; fractures and proximal humerus fractures, a gourd-shaped inflatable device is used to compact the bone marrow.

This is a continuation-in-part application of application Ser. No.07/308,724, filed Feb. 9, 1989, entitled "Surgical Protocol for Fixationof Osteoporotic Bone Using Inflatable Device," now U.S. Pat. No.4,969,888.

This invention relates to improvements in the surgical treatment of boneconditions of the human and other animal body systems and, moreparticularly, to a method and apparatus for use in correcting suchconditions.

BACKGROUND OF THE INVENTION

Every year in the United States there occurs over 1.2 million bonefractures of osteoporotic bone. Over nine hundred thousand (900,000) ofthose fractures occur in bones which can be treated with thepercutaneous balloon technology of the present invention which includesinstant fixation by methyl methacrylate cement or with liquid artificialbone substitutes. Those fractures which can be treated by the method andapparatus of the present invention are distal radius fractures, theproximal humerus fractures, the vertebral body compression fractures,and fractures of other long bones.

Osteoporotic and non-osteoporotic vertebral body compression fracturesare currently treated with bed rest, analgesics, and intravenoushydration during the first week after onset of the problem. These stepsare followed by the prescription of a soft or firm spinal corset,depending upon the physician's preference. In most cases, the corset isnot worn because the patient suffers much discomfort and oftentimesgreater discomfort than that due to the fracture of the vertebral body.The fracture pain lasts from two to eight months. In many cases,patients with vertebral body collapse fractures require about one weekin an acute care hospital and two to three weeks in an extended carefacility until they are able to move about independently and with onlymoderate pain. Current treatment does not substantially alter theconditions of the vertebral body.

The current management of shoulder fractures includes either long termimmobilization in a sling, followed by lengthy physical therapy. If thefracture is in three or four parts, the fracture is treated with ashoulder hemiarthroplasty. Long term stiffness is the rule, followingeither treatment due to long term immobilization and/or extensive woundhealing.

Colles' fractures of the wrist in the elderly are currently treated inthree different ways: 1) they are treated with closed reduction andapplication of a short arm cast for one or more weeks; 2) they can betreated with a short arm cast without reduction; and 3) they may betreated with closed reduction and pins and plaster immobilization foreight weeks. All treatment modalities result in considerable stiffnessand have frequent malunions of the fractures.

Because of the problems associated with the treatment of vertebral bodyfractures, Colles' fractures, shoulder fractures and other boneconditions similar thereto, a need has existed for a method andapparatus to improve on the protocol for treating such fractures such asshortening the time in which a patient suffers pain due to suchfracture. The present invention provides apparatus and a method ofpercutaneous fracture fixation which satisfies this need.

SUMMARY OF THE INVENTION

This invention relates to a method and apparatus for the fixation offractures of osteoporotic and non-osteoporotic bones. The invention isespecially suitable for use in the fixation of osteoporotic vertebralbody compression fractures, Colles' fractures and fractures of theproximal humerus. The method of the present invention includes a seriesof steps including forming an incision in the body and penetrating thebone having the fracture with instruments including a guide pin and acannula, drilling the bone marrow of the bone to enlarge the cavity orpassage to be treated, following which an inflatable device, such as anexpandable balloon, is inserted in the cavity and inflated. Theexpansion of the balloon causes a compacting of the bone marrow againstthe inner surface of the outer cortical wall of the bone to be treatedto further enlarge the cavity. Then, a flowable synthetic bone materialor methyl methacrylate cement is directed into the cavity and allowed toset to a hardened condition. Following this, the instruments are removedand the incision in the skin is covered with a bandage.

In the fixation of vertebral body fractures, an elliptical inflatabledevice is first used, if needed, to initiate the compacting of the bonemarrow and to commence the formation of a cavity or passage in the bonemarrow, following which a larger inflatable device is inserted into thecavity to further compact the bone marrow in all directions. In thefixation of Colles' fractures and proximal humerus fractures, agourd-shaped inflatable device is used to compact the bone marrow.

It is the intention of the present invention to provide, in each case ofa fracture of osteoporotic or non-osteoporotic bone, an inflatabledevice that has a shape of or the ability to conform to the internalsurface configuration of the cortical bone in which the device is used.Thus, the inner surface configuration of the cortical bone of avertebral body is disk-shaped or checker-shaped, the cortical bone ofdistal radius is gourd-shaped and the cortical bone of the proximalhumerus is also gourd-shaped.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a patient about to undergo the surgicaltreatment of vertebral body fixation in accordance with the method ofthe present invention, the patient lying prone on a U-shaped holder;

FIG. 2 is a front elevational view of the patient on the holder;

FIG. 3 is a side elevational view of the patient, showing hyperextensionof the spine of the patient;

FIG. 4 is a perspective view of the rear portion of the patient showingthe patient lying between the sides of the holder;

FIG. 5 is a stabilizer bracket for a guide pin and a cannula formingparts of the apparatus for carrying out the method of the presentinvention;

FIG. 6 is a perspective view of the patient holder shown in FIGS. 1, 2and 4;

FIG. 7 is another perspective view of the holder of FIG. 6 lookingupwardly from the bottom thereof;

FIG. 8 is a top plan view of the portion of the patient showing severalvertebral bodies of the patient and the way in which the a guide pinenters a patient for carrying out the method of the present invention;

FIG. 9 is a schematic front elevational view of the patient and avertebral body of the patient showing the entry angles of the guide pinof the apparatus of the present invention;

FIG. 10 is a side elevational view of the vertebrae, showing a guide pininserted into one of the vertebral bodies;

FIG. 11 is a top plan view of the guide pin inserted into the vertebralbody;

FIG. 12 is a perspective view of the guide pin placed within thevertebral body and a tissue expander sliding on the guide pin to thevertebral body;

FIG. 13 is a side elevational view of the tissue expander over the guidepin;

FIG. 14 is a view similar to FIG. 12 but showing a cannula carried bythe tissue expander toward the vertebral body;

FIG. 15 is a view similar to FIG. 13 but showing teeth of the cannulaembedded in the outer wall of the vertebral body;

FIG. 16 is a view similar to FIG. 14 but showing another view of thecannula embedded in the cortical wall of the vertebral body;

FIG. 17 is a view similar to FIG. 15 but showing the withdrawal of thetissue expander through the cannula;

FIG. 18 is a view similar to FIG. 11 but showing a drill guided into thevertebral body by the guide pin through the cannula;

FIG. 19 is an enlarged perspective view of the drill of FIG. 18;

FIG. 20 is a view similar to FIG. 18 but showing an ellipticalinflatable device inserted into the vertebral body to expand the bonemarrow in the vertebral body;

FIG. 21 is a checker-shaped inflatable device in the vertebral body tocomplete the expansion of the bone marrow in the vertebral body;

FIG. 22 is a top plan view of the checker-shaped inflatable device ofFIG. 21;

FIG. 23 is a side elevational view of the checker-shaped inflatabledevice of FIG. 22;

FIG. 24 is a view similar to FIGS. 20 and 21 but showing the insertionof the inflatable device of FIG. 22 into a vertebral body;

FIG. 25 is a view similar to FIG. 24 but showing the insertion of aliquid artificial bone or methyl methacrylate cement into the vertebralbody to replace the bone marrow;

FIG. 26 is an enlarged, fragmentary perspective view for directingliquid bone or methyl methacrylate cement into the vertebral body;

FIG. 27 is a side elevational view of the vertebral body after theliquid bone has been injected into the interior thereof;

FIG. 28A is a schematic side view of a vertebral body showing theinitial insertion of an elliptical inflatable device in the vertebralbody and before inflation of the device;

FIG. 28B is a view similar to FIG. 28A but showing partial inflation ofthe inflatable device of FIG. 28A to initiate a cavity or passage in thebone marrow of the vertebral body;

FIG. 28C is a view similar to FIG. 28B but showing a checker-shapedinflatable device in the vertebral body to further compact the bonemarrow in the vertebral body;

FIG. 28D is a view similar to FIG. 28C but showing the initial injectionstage in which liquid bone or methyl methacrylate cement is injectedinto the vertebral body;

FIG. 28E is a view similar to FIG. 28D but showing the vertebral bodyafter the liquid bone or methyl methacrylate cement has set to ahardened condition;

FIG. 29 is a schematic top plan view of a distal radius fracture of thewrist, the fracture at the end of the radius being aligned with Chinesefinger traps;

FIG. 30 is a view similar to FIG. 29 but looking in a differentdirection at the hand but illustrating the fracture;

FIG. 31 is a view of the fracture with the guide pin being insertedthrough the interface of the fracture;

FIG. 32 is a view similar to FIG. 31 but showing a drill in the radius,and the area to be filled with liquid bone or methyl methacrylatecement;

FIG. 33 is a side elevational view of a shoulder showing a fracturetherein; and

FIG. 34 is a view similar to FIG. 33 but showing the bone fracture andcavity to be filled with liquid bone or methyl methacrylate cement.

DETAILED DESCRIPTION OF THE DRAWINGS

Percutaneous vertebral body fixation is indicated for all causes ofspontaneous osteoporotic or non-osteoporotic vertebral body collapsefractures except those due to infection or neoplasia. The etiology ofthe bone marrow should be diagnosed prior to fixation. Concomitantendocrine therapy, chemotherapy or radiation is not contraindicated withpercutaneous vertebral fracture fixation.

Impending vertebral body collapse as determined by the presence ofprevious collapse fractures and increased uptake on technetium-99 bonescan in a non-collapsed vertebral body. Various CT density values mayeventually correlate with impending vertebral body collapse and beutilized to predict impending vertebral body fractures.

Contradictions of such fixation are as follows:

Presence of pyogenic infection;

Presence of tuberculous infection;

Presence of neoplasia;

Presence of sepsis;

High velocity spinal fractures;

Fractures above the level of T-6; and

Fractures which demonstrated widened pedicles on AP spine x-rays.

To illustrate the teachings of the present invention, the followingspecification will be described with respect to treatment of fracturesrelating to osteoporotic bone, but it is to be understood that theinvention applies also to treatment of fractures relating tonon-osteoporotic bone.

In carrying out the teachings of the method of the present invention asto osteoporotic vertebral fixation, a patient 10 is placed on agenerally U-shaped holder 12 so that the patient lies above the centralpart 14 of holder 12 and between a pair of spaced sides 16 and 18 asshown in FIGS. 1, 2 and 4. Holder 12 can be of any suitableconstruction, such as metal or plastic and is constructed to render thepatient generally immovable when the patient is prone as shown in FIGS.1-4. The length of sides 16 and 18 is preferably sufficient to achievethe aim of rendering the patient generally immovable.

Typically, the length of sides 16 and 18 is approximately 12 to 15inches. For the comfort of the patient, a cushion 20 is provided abovecentral part 14 as shown in FIG. 2. The central part 14 has holes 22therethrough (FIGS. 6 and 7) and the holes are for the purpose ofreceiving circular portions of the cushion 20 formed due to the weightof the patients to anchor the cushion in place and to prevent it frommoving relative to holder 12 when the patient's body is on the cushionas shown in FIG. 2. This assures that the cushion will not contribute tothe movement of the patient relative to the holder. Pads 24 and 26 areplaced at the chest and hip regions of the patient for the comfort ofthe patient and to extend the spine.

FIG. 5 shows a support bracket 28 adjustably mounted on the sides 16 and18 of holder 12. The purpose of bracket 28 is to support a cannula 30and guide pin 70 forming part of the apparatus of the present invention.Cannula 30 will be described hereinafter in more detail.

Bracket 28 includes a pair of clamps 31 and 32 for releasably connectingthe bracket to respective sides 16 and 18 of holder 12 by means of thumbscrews 34. Bracket 28 further includes a pair of legs 38 and 40 whichare made up of connectable extensions as shown in FIG. 5. Legs 38 and 40are releasably connected to respective clamps 31 and 32 by thumb screws42 and 44. A rod 46 is connected by thumb screws 48 and 50 to endsleeves 52 and 54 on the upper ends of respective legs 38 and 40. Rod 46can be rotated in the sleeves 52 and 54 to thereby rotate a clamp 56coupled to the rod 46 and having a leg 58 on which cannula 30 and guidepin 70 are adjustably mounted. Thus, the cannula can be moved toward oraway from legs 38 and 40 and can rotate about the longitudinal axis ofrod 46. In this way, the cannula can be adjusted as to the distance fromthe patient to rod 46 as well adjust the position of the bracket 28 bymeans of shifting clamps 31 and 32 along the sides of holder 12.

The teachings of the method of the present invention will be hereinafterdescribed with respect to treatment of a person with osteoporotic spinedisease. The presence of such disease is evidenced by a plain filmspinal x-rays and either CAT-scan evidence of impending fracture orplain film x-ray evidence of vertebral body collapse. In obtaining suchevidence, both sagittal and coronal CAT-scans should be obtained beforethe performance of the method of the present invention. The coronal scanis also needed to determine the width of the vertebral body which is tobe treated and also to rule out the presence of posterior displacementof the colon which can interfere with the posterolateral approach whichgenerally occurs in four percent of the patients. If the colon is noted,the approach must be altered to the other side of the body.

The sagittal CAT-scan is needed to determine the height of the vertebralbody to be treated. If an acute compression fracture is present, thenthe appropriate height is determined by the height of the vertebral bodylocated superior to the fracture. If the patient has an acute fractureof a vertebral body, the patient is to be placed prone in the mannershown in FIGS. 1-4.

Attempts to reconstitute the height of the vertebral body should be madeby hyperextending the patient's spine as shown in FIG. 3. If the patienthas an impending fracture of a vertebral body, then the patient can bepositioned either prone as shown in FIGS. 1-4 or on his side dependingupon the surgeon's preference. If on the side, the patient is renderedimmovable by suitable structure for holding the patient in one positionduring the time that the method of the present invention is beingperformed.

The posterolateral approach is used whether the patient is prone (FIGS.1-4) or in the lateral position. Then the entry point on the skin isdetermined radiologically and is located approximately 10 cm from themidline and just inferior to a rib if present at that level as shown inFIG. 8.

FIG. 8 shows the entry points of the instruments for carrying out themethod of the present invention for two vertebral bodies spaced fromeach other. The instrument shown in FIG. 8 is a guide pin 70 whichenters the patient at an incision 62 (FIG. 8). A choice of angle ofentry of the guide pin 70 can be 30° to 45° as shown in FIG. 9. Thevertebral body to be injected is located fluoroscopically. The skin,underlying soft tissue and lateral cortex of the vertebral body areinjected with a long spinal needle. General anesthesia is not advisable.

The surgical procedure for treating a vertebral body is as follows:

The vertebral body 66 to be treated (FIGS. 10 and 11) is penetrated bythe pointed end 68 of quide pin 70 which enters the vertebral bodybetween the inferior and superior end plates of the body 66 and into theposterior quarter of the vertebral body. Pedioles are to be ignored. Thequide pin penetrates to a depth in the range of 60 to 80% acrossvertebral body 66 as shown in FIG. 11. Placement of the pin isfluoroscopically monitored. Any further penetration beyond 70% runs therisk of perforation of the vertebral body and an adjacent major vesselor lung.

With the guide pin penetrating the vertebral body 66 as shown in FIGS.10 and 11, a soft tissue expander 71, which is a tubular member as shownin FIGS. 12 and 13, is inserted over the guide pin until the end of theexpander makes contact with the vertebral body as shown in FIG. 13.Expander 71 then forms a guide for cannula 30 to guide the cannulatoward the vertebral body to be treated.

When the cannula makes contact with the wall of the vertebral body, thecannula is rotated clockwise under pressure to force the teeth 31 of thecannula into the wall of the vertebral body 66 as shown in FIG. 15. Thislocks the cannula into the wall as shown in FIG. 16 so that the cannulacan be coupled to bracket 28 (FIG. 5) for stabilization thereby. Then,the expander 71 can be removed from the interior of cannula 30 as shownin FIG. 17.

Once the cannula is stabilized, a drill stop is formed to preventpenetration of the far cortex of the vertebral body by drill 72 (FIGS.18 and 19). The drill stop is formed by a shoulder 67 on pin 70 (FIG.19) which is engageable with shoulder 69 on drill 72 and holding pin 70with bracket 28.

Vertebral body 66 is drilled by a 4 mm drill 72. The drilling depth ismonitored by fluoroscopy to the end of the guide 10. The drill istubular and is guided by the guide pin 70 as shown in FIG. 19.

The next step to be performed in carrying out the method of the presentinvention is to withdraw the pointed guide pin 70 and replace it with adeflated elliptical or chambered bladder device 65. The ellipticalballoon 65 is monitored fluoroscopically. This is achieved by inflatingthe elliptical balloon 65 to a pressure in the range of 50 to 300 psiwith a radio-opaque contrast medium by an injector as shown in FIG. 24.The purpose of the elliptical balloon 65 is to center a second,checker-shaped inflatable device or balloon 76 (FIGS. 21-23) in theinterior of vertebral body 66. After the elliptical balloon 65 isdeflated and removed, checker-shaped or cylindrically shaped device orballoon 76 is inserted into the cannula and directed into the interiorof vertebral body 66 as shown in FIG. 21.

The diameter of balloon 76 is determined by the pre-operative CAT-scanresults. The diameter is in the range of 1.0 cm to 3.5 cm. The axialheight of the balloon (FIG. 23) is determined by the intra-operativereduction height of the vertebral body fracture. The height is in therange of 0.5 cm to 4.0 cm. If the balloon placement is somewhateccentric, a smaller balloon may be needed. The balloon 76 has a neck77, and the outer configuration of the balloon 76 is substantially thesame as that of the inner surface of the cortical wall of the vertebralbody 66.

The progress of balloon inflation is monitored fluoroscopically toensure proper insertion of the balloon 76. The balloon is injected,gradually, with contrast as in the case of the elliptical balloon to amaximum height. This may require pressure as great as 300 psi toaccomplish. The balloon's inflation should be monitored on the lateralfluoroscopic view of the spine. Posterior displacement of the bone intothe spinal canal or full expansion of balloon 76 signals the terminationof the chamber preparation. Further expansion of the balloon at thispoint could result in spinal cord or root injury.

As balloon 76 is inflated, it forces the osteoporotic bone marrow 67laterally and outwardly of the wall of the vertebral body 66. Thiscompacts the bone marrow and leaves a void in the interior of thevertebral body to be treated. The compacted bone marrow forms a dam toblock any fracture of the vertebral body. Thus, when liquid syntheticbone or methyl methacrylate cement is forced into the void, thecompacted bone marrow will substantially prevent flow through thefracture.

After the balloon 76 has been deflated it is removed from the cannula30. An irrigation nozzle (not shown) is then inserted into the vertebralbody 66. Irrigation is performed with normal saline solution. Irrigationshould be performed until the effluent is reasonably clear.

After the vertebral body has been irrigated, the artificial bonesubstitute, which may include a synthetic bone or methyl methacrylatecement, is injected into the void left by the inflation of balloon 76. Adouble barrel injection gun nozzle aspirates constantly through theshort barrel. Such injection gun nozzle is shown in FIGS. 25 and 26 andincludes a material delivery tube 80 and an aspirating tube 82, both ofwhich have open ends 84 and 86, respectively. Injection of syntheticbone material is monitored using lateral fluoroscopy. Leakageposteriorly into the canal of tube 82 requires an abrupt stopping of theinjection. Leakage anteriorly is exceedingly rare since the anteriorlongitudinal ligament is intact with these fractures.

The volume of injection ranges between 3 and 5 cc's. A larger volume isinjected than one would predict from the size of the chamber formed withballoon 76 even in those patients injected prophylactically.

The injection gun nozzle shown in FIG. 26 is slowly removed as thevertebral body is injected with artificial bone or cement. At the entryhole into the vertebral body the tip of the injection nozzle is twistedas the cement sets up. At that time, the injection gun nozzle should beremoved. FIGS. 28A and 28B show the sequence of the expansion ofelliptical balloon 65. FIGS. 28C and 28D show checker-shaped balloon 76in the vertebral body 66. FIG. 28E shows the vertebral body after themass 81 of artificial bone or methyl methacrylate cement has set to ahardened condition.

After the proper volume of artificial bone or cement has been insertedinto the void of the vertebral body, cannula 30 is removed and the skinis dressed with a bandage.

Surgical protocol for Colles' fractures are described as follows withreference to FIGS. 29-32.

The current treatment for distal radius fractures of the wrist inosteoporotic patients includes: (1) closed reduction and application ofa short arm cast with the wrist in a flexed position for six weeks; (2)application of a short arm cast without reduction of the fracture; and(3) closed reductions of the fracture with Chinese finger traps andapplication of pins and plaster. All three techniques require castimmobilization for 6 to 8 weeks and result in considerable stiffness formany months. In the case of the second treatment described, the wrist isalso malpositioned.

The treatment of the present invention involves the reduction of thefracture with Chinese finger traps and the subsequent use of a balloonto create a chamber followed by the injection of either methylmethacrylate cement or a flowable bone substitute into the chamber tofix the fracture. Immobilization would only be a removable splint fortwo to four weeks. The wrist would be exercised daily to prevent thesubsequent stiffness which usually follows wrist fracture.

The steps involved in this procedure are the same as those listed forthe percutaneous fixation of vertebral body fractures. The Colles'fracture is positioned this time using finger traps 90 as shown in FIGS.29 and 30. Local anesthesia is injected. The hand and forearm areprepped in the usually sterile fashion. A smooth guide pin 92 (FIG. 31)is inserted from the tip of the styloid at a 45° angle across thefracture 93. This is followed by a soft tissue expander and then a 2 mmcannula 91. A 2 mm drill 94 (FIG. 32) is then used to drill a canal orpassage across the fracture using fluoroscopic control. The drill andguide pin are removed and a gourd-shaped distal radius balloon 95 isintroduced into the fracture region through the cannula. The balloon 95has a configuration substantially the same as that of the inner surfaceof the cortical bone. The deflated diameter of a globe-shaped part 95aof balloon 95 is in the range of 7 to 10 mm, the overall length L is inthe range of 4 to 7 cm, and cylindrical part 95b has a length in therange of 5 to 8 mm.

The balloon 95 is expanded with contrast liquid using x-ray control.Expansion of the balloon 95 causes compacting of the osteoporotic bonemarrow against the inner surface of the cortical wall. The balloon isthen deflated and the cavity is then injected with a mass 97 of eithermethyl methacrylate cement or liquid bone substitute. A splint is usedfor two to four weeks.

Surgical protocol for the percutaneous fixation of proximal humerusfractures is as follows, with reference to FIGS. 33 and 34:

Percutaneous intra-osseous balloon fixation is indicated for allone-part shoulder fractures (i.e. non-displaced shoulder fractures), alltwo-part shoulder fractures except greater tuberosity fractures, and allthree-part fractures that do not include a prominent elevation of thegreater tuberosity or could be better treated with a hemiarthroplasty.It is not now indicated for four-part fractures.

The fracture is reduced with the patient sitting upright. The fractureis injected with local anesthesia as is the area just posterior to thegreater tuberosity where a guide pin will be introduced. The fracture isreduced with traction and held by an assistant. A guide pin isintroduced through the head of the humerus just posteriorly to thegreater tuberosity and followed fluoroscopically across the fracture toapproximately 8 cm below the fracture. The soft tissue expander isintroduced followed by the 3 mm cannula. A canal is drilled over theguide pin with a 3 mm drill 100 and the drill and guide pin are removed.

A gourd-shaped proximal humerus inflatable device or balloon isintroduced into the cavity and inflated using contrast and fluoroscopiccontrol. The balloon is then removed and then the cavity is injectedwith a mass 101 of either methyl methacrylate cement or a liquidartificial bone substitute as shown in FIG. 34. The fracture is helduntil the injected substance hardens. The entry site on the top of theshoulder is dressed with a steri-strip and the patient is given a slingfor 2 to 4 weeks. During those weeks, the patient should remove thesling several hours a day but perform no heavy lifting.

The gourd-shaped proximal humerus balloon has a configurationsubstantially the same as that of balloon 95 (FIGS. 31 and 32). Thediameter of the globe-shaped part of the proximal humerus balloon is inthe range of 14 to 20 mm. The diameter of the cylindrical part is in therange of 6 to 8 mm, and its length is in the range of 8 to 14 cm.

We claim:
 1. A method of fixation of a fracture or impending fracture ofa bone having bone marrow therein comprising:forming a passage in thebone marrow; compacting the bone marrow to increase the volume of saidpassage; and filling the passage with a flowable material capable ofsetting to a hardened condition.
 2. A method as set forth in claim 1,wherein said compacting step includes forcing the bone marrow outwardlyand against the site of the fracture or impending fracture.
 3. A methodas set forth in claim 1, wherein said compacting step includes forcingthe bone marrow outwardly of the central portion of the bone.
 4. Amethod as set forth in claim 3, wherein said forcing step includesdirecting the bone marrow against an inner surface of the bone withinthe fracture or impending fracture.
 5. A method as set forth in claim 1,wherein said compacting step includes inflating an inflatable device insaid passage to urge the bone marrow therein.
 6. A method as set forthin claim 5, wherein is included the step of inserting the device in thepassage before the inflating step.
 7. A method as set forth in claim 1,wherein is included the step of inserting an inflatable device in saidpassage, said increasing step including inflating the device to forcethe bone marrow outwardly of said passage.
 8. A method as set forth inclaim 1, wherein said forming step includes drilling said bone marrow toform said passage.
 9. A method as set forth in claim 8, wherein saiddrilling step includes guiding a drill through and into the proximatecortical bone marrow.
 10. A method as set forth in claim 8, wherein saidforming step includes drilling the bone marrow to a predetermined depth.11. A method as set forth in claim 10, wherein said depth is in therange of approximately 60 to 80% of the maximum oblique dimension of thebone containing the bone marrow.
 12. A method as set forth in claim 1,wherein the fracture is a fracture of a vertebral body of the humanspine.
 13. A method as set forth in claim 1, wherein said fracture is aColles' fracture of the distal radius.
 14. A method as set forth inclaim 1, wherein said fracture is a fracture of the proximal humerus.15. A method as set forth in claim 1, wherein said flowable material isselected from the group consisting of liquid synthetic bone and methylmethacrylate cement.
 16. A method of fixation of a fracture of a bonecontaining bone marrow therein comprising:drilling said bone to form arecess therein; inserting an inflatable device in said recess; inflatingthe device in the recess to increase the volume thereof and to force thebone marrow outwardly of the recess to form a void in the bone; andfilling the void in the bone with a flowable material capable of settingto a hardened condition.
 17. A method as set forth in claim 16, whereinsaid inflating step includes inflating a chambered bladder device havingan elliptical configuration.
 18. A method as set forth in claim 16,wherein said inflating step includes inflating a chambered bladderdevice having generally cylindrical configuration.
 19. A method as setforth in claim 16, wherein is included the step of guiding a drill intothe bone.
 20. A method as set forth in claim 16, wherein said inflatingstep includes inflating the device with a radio-opaque material.
 21. Amethod as set forth in claim 16, wherein said inflating step includescompacting the bone marrow in the bone.
 22. A method as set forth inclaim 16, wherein said inflating step includes forcing the bone marrowoutwardly of the central portion of the bone.
 23. A method as set forthin claim 22, wherein said inflating step includes compacting the bonemarrow against an inner surface of the bone.
 24. A method as set forthin claim 16, wherein said drilling step includes guiding a drill intothe bone, and rotating the drill about its longitudinal axis.
 25. Amethod as set forth in claim 24, wherein said drilling step includesdrilling the bone marrow to a predetermined depth.
 26. A method as setforth in claim 25, wherein said depth is in the range of approximately60 to 80% of the maximum oblique dimension of the bone.
 27. A method asset forth in claim 16, wherein the fracture is a fracture of a vertebralbody of the human spine.
 28. A method as set forth in claim 16, whereinsaid fracture is a Colles' fracture of the distal radius.
 29. A methodas set forth in claim 16, wherein said fracture is a fracture of theproximal humerus.